Sustainable Management of Soil Resources in Wadi Wardan, Suez Gulf Region, Southwestern Sinai, Egypt

Abstract

Egypt's land resources deteriorate due to soil mismanagement under the limited natural resources while the population increases. This issue highlights the importance of efficient soil resource management to increase crop yield and meet growing food needs. This study offers sustainable soil resource management for each soil type in Wadi Wardan, Suez Gulf region, South Sinai, Egypt, maximizing land usage and crop output while avoiding soil degradation. Wadi Wardan, spanning 300 km 2 , is believed to hold promising soil resources in South Sinai. From upslope to downslope, five landforms were mapped in Wadi Wardan: the recharge area of Wadi tributaries (33 km 2 ; unsampled), pediment (105 km 2 ), fluvial plain (54 km 2 ), Wardan's delta (87 km 2 ), and coastal plain (21 km 2 ). Eightynine pedons were proportionally dispersed over only four landforms in Wadi Wardan. Soils range from shallow to deep, with well-drained to poorly-drained conditions. The studied soils were coarse-to-fine in texture. Soils range from nonsaline on upslopes to very strongly saline on downslopes. The studied soils rangefromslightlytoextremelycalcareous.Highρbvaluesandloworganiccarbonlevelsindicated soil problems in Wadi Wardan. Six mapping units were established depending on soil depth, texture, salt, and lime content. Based on WRB soil taxonomy, most soils in the pediment and fluvial plains are classed as Leptosols (69.3 km 2 ), Regosols (42.5 km 2 ), and Calcisols (39.7 km 2 ), while those in Wardan's delta are Sololnetz (43 km 2 ) and Solonchaks (51.5 km 2 ). Coastal plain soils are classified as Arenosols (21 km 2 ). Based on WRB, Solonchaks has a horizon sequence of A-Btz-C/Bt-Cz containing salic horizon and soil limitations related to high salinity content (9.1-21.1 dS/m). Natric and salic horizons in Sololnetz's Ap-E-Btnz-C sequence indicate sodium and salt restrictions. The Arenosol layer sequence (A-Ck-Cq-Cz-Cφ)suggestsdeepsandy-saline soil, while the Leptosol layer sequence (C-Cφ)showsshallowsandysoil with over 30% rock fragments. Each soil type requires unique management depending on dominating features that limit plant development. The current study proposed a sustainable soil management framework for each soil type identified in the study. Incoherence, nutrient storage, and erosion sensitivity plague Arenosols. Salts affect three types of soils under study to varying degrees: saline sandy soils (Arenosols) with a coarse texture that end at a depth of 172 cm, and salts are concentrated in the lower layers (Cz layer at a depth of 106-153 cm) of the pedon, reaching more than 27 dS/m. The strongly saline soils, particularly in the upper 50 cm of the pedon, have a moderately fine textured soil, particularly in the salic horizon (Btz) in Solonchaks, which finishes at 149 cm deep. The third kind is represented by Sololnetz with a fine texture, and it is the most harmful because it combines high salinity and high alkalinity in the fine texture of the soil, as in the Btnz horizon at a depth of 57-100 cm. Each of these soil types has a uni...